Difference between revisions of "1995 AIME Problems/Problem 12"

 
m
Line 1: Line 1:
 
== Problem ==
 
== Problem ==
 +
Pyramid <math>\displaystyle OABCD</math> has square base <math>\displaystyle ABCD,</math> congruent edges <math>\displaystyle \overline{OA}, \overline{OB}, \overline{OC},</math> and <math>\displaystyle \overline{OD},</math> and <math>\displaystyle \angle AOB=45^\circ.</math>  Let <math>\displaystyle \theta</math> be the measure of the dihedral angle formed by faces <math>\displaystyle OAB</math> and <math>\displaystyle OBC.</math>  Given that <math>\displaystyle \cos \theta=m+\sqrt{n},</math> where <math>\displaystyle m_{}</math> and <math>\displaystyle n_{}</math> are integers, find <math>\displaystyle m+n.</math>
  
 
== Solution ==
 
== Solution ==
  
 
== See also ==
 
== See also ==
 +
* [[1995_AIME_Problems/Problem_11|Previous Problem]]
 +
* [[1995_AIME_Problems/Problem_13|Next Problem]]
 
* [[1995 AIME Problems]]
 
* [[1995 AIME Problems]]

Revision as of 00:28, 22 January 2007

Problem

Pyramid $\displaystyle OABCD$ has square base $\displaystyle ABCD,$ congruent edges $\displaystyle \overline{OA}, \overline{OB}, \overline{OC},$ and $\displaystyle \overline{OD},$ and $\displaystyle \angle AOB=45^\circ.$ Let $\displaystyle \theta$ be the measure of the dihedral angle formed by faces $\displaystyle OAB$ and $\displaystyle OBC.$ Given that $\displaystyle \cos \theta=m+\sqrt{n},$ where $\displaystyle m_{}$ and $\displaystyle n_{}$ are integers, find $\displaystyle m+n.$

Solution

See also